Triple Net Lease Calculator

In a triple net lease, the tenant pays base rent plus three additional categories of expenses: property taxes, building insurance, and common area maintenance (CAM). This calculator helps estimate total occupancy cost so both landlords and tenants can evaluate deal economics clearly.

Understanding the Components

Base Rent

The fixed rent amount, typically quoted per square foot per year. In a triple net lease, this is just the starting point—the "net" expenses are added on top.

Property Taxes

Your proportionate share of the property's annual tax bill. In Washington, property tax rates vary significantly by county and are reassessed regularly. The landlord pays the full tax bill and passes through each tenant's share based on the percentage of the building they occupy.

Building Insurance

Your share of the landlord's property insurance for the building structure. This is separate from any liability or contents insurance you carry for your own business operations.

Common Area Maintenance (CAM)

Operating costs for shared spaces and building services—landscaping, parking lot maintenance, common area utilities, janitorial, security, property management fees, and general repairs. CAM is often the largest variable component and the one most important to understand in detail.

Washington State Considerations

Washington has no state income tax, but property taxes fund local services and can vary substantially depending on location. When evaluating NNN costs, keep these factors in mind:

Property Tax Variation

Property tax rates in Washington range roughly from $8 to $14 per $1,000 of assessed value depending on the county and local levies. Seattle and King County tend toward the higher end; eastern Washington counties are generally lower. Your per-SF tax pass-through depends on the building's assessed value and your pro-rata share.

County	Typical Range (per $1,000 assessed)
King County (Seattle)	$9.00 – $12.00
Pierce County (Tacoma)	$10.00 – $13.00
Snohomish County	$9.50 – $11.50
Spokane County	$10.00 – $12.50
Clark County (Vancouver)	$9.00 – $11.00

Note: These are approximate ranges and vary by specific location, levy district, and assessment year.

Leasehold Excise Tax

If you're leasing space from a public entity (such as a port authority or municipality), Washington imposes a leasehold excise tax of 12.84% on rent payments. This is less common but worth noting if you're considering space in a publicly-owned facility.

CAM Reconciliation

Most NNN leases require annual CAM reconciliation, where actual expenses are compared against estimated payments. If actual costs exceeded estimates, you'll owe additional payment; if costs were lower, you may receive a credit. Review your lease to understand the reconciliation timeline and audit rights.

Comparing Lease Quotes

When evaluating multiple spaces, always compare the total occupancy cost—not just the base rent. A space quoted at "$24 NNN" could cost significantly more than one quoted at "$30 gross" depending on the actual pass-through expenses.

For landlords, clearly presenting estimated NNN costs upfront helps tenants evaluate the space accurately and reduces friction later in negotiations. For tenants, getting detailed NNN estimates—and understanding whether they're capped—is essential to accurate budgeting.

Using This Calculator

This calculator provides estimates based on the figures you enter. Actual costs depend on your specific lease terms, the landlord's expense allocations, and annual reconciliation. Use it as a planning tool, but review the actual lease language and expense history before making commitments.

If you're evaluating a lease and need help understanding the NNN provisions, expense caps, or reconciliation terms, an attorney can review the specific language and identify areas for negotiation.